Supported nano-sized Ce0.8Eu0.2O2-δ solid solution catalysts for diesel soot and benzylamine oxidations

The present work describes the role of oxide supports such as alumina (Al2O3), silica (SiO2), and titania (TiO2) on the structural and catalytic properties of europium ion-doped cerium oxide. In particular, the main motive of this study was to further improve the catalytic efficiency of Ce0.8Eu0.2O2-δ solid solutions for oxidation reactions. Diesel soot oxidation and oxidative coupling of benzylamine were examined as model reactions to assess the catalytic properties of the prepared materials. These were prepared by deposition coprecipitation method and characterized by various techniques namely, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and BET/BJH surface area and pore-size distribution methods. The characterization studies reveal that Ce0.8Eu0.2O2-δ is well-dispersed without the formation of CeO2 or Eu2O3 crystalline compounds over the surface of various supports. The TEM studies confirm the nano-crystalline nature of the Ce0.8Eu0.2O2-δ and Raman studies indicate the formation of oxygen vacancies which are significant for oxidation reactions. As expected, the supported Ce0.8Eu0.2O2-δ mixed oxides exhibited better catalytic activity than pure ceria and unsupported oxides towards the soot and benzylamine oxidation reactions. Supported Ce0.8Eu0.2O2-δ(CE) catalysts are exhibiting better performance than unsupported CE and pure ceria for soot and benzylamine oxidation owing to metal oxide-support and metal oxide-metal oxide interactions.